In the manufacture of various types of garments, it is sometimes desirable to provide a pocket at a location on the garment where no seam exists. Such a pocket is commonly referred to as a "set-in" pocket. For example, in the manufacture of tubular knit pants, a seam is created down the front and back of the pants, but the sides of the pants, where pockets typically are provided, are seamless. Other types of garments requiring a set-in pocket may be hooded sweat shirts, sweat pants, placket front shirts, and slacks.
One method for sewing a pocket at a seamless position on a garment is to overlay a pocket piece of material onto the garment material, sew two parallel rows of stitches through both of the materials, and cut the two overlying materials between the two rows of stitches. The resulting stitched and cut overlying materials can then be everted and formed into a pocket with a few additional sewing operations. In the past, the cutting step of such a method typically was a manual operation, and as a result sometimes required the production of low-cost garments with set-in pockets to be carried out in third world countries where labor is inexpensive. However, cloth cutting attachments for double needle sewing machines have been devised that, in conjunction with the sewing needles, automatically stitch and cut the overlying pieces between the lines of stitching in one operation.
Prior cloth cutter attachments such as U.S. Pat. No. 2,581,046 include a cutter blade that is carried by the reciprocating needle bar of the sewing machine and is pivotable so as to first cut the cloth ahead of the stitches being formed at the beginning of the lines of stitching and later is pivoted to cut the cloth behind the stitches being formed at the ends of the lines of stitching. Such cloth cutter attachments have included a non-reciprocating lever for changing the position of the cutter, and holding the cutter in its position after movement. These early prior art cloth cutter attachments typically have required complex systems for moving the cutter between its cutting positions, and generally are relatively slow and cumbersome in operation. Therefore, the garments on which these prior art devices are used usually are relatively expensive due to its increased production time.
Recently, cloth cutter attachments have been developed that are slidably mounted upon the needle chuck of the reciprocating needle bar of the sewing machine and have an actuator mounted to the sewing machine frame or housing. For example, U.S. Pat. No. 5,373,798 discloses a cloth cutter attachment for a sewing machine that includes a needle chuck mounted to the reciprocating needle bar of the sewing machine, and to which the needles of the machine are mounted. A cutting blade assembly is slidably received within a slotted opening formed through the needle chuck and includes a cutting blade that extends downwardly through the chuck from a sliding support bar positioned between the needles. The cutting blade support bar is moved longitudinally along the slot formed in the needle chuck, to move the cutting blade between curing positions ahead of and behind the sewing needles.
A problem with such sliding cloth cutter attachments typically has been that the size of the needle chuck necessary to accommodate the sliding cutter support bar requires the sewing machine to be modified so that the needle chuck can be mounted in a position so as not to interfere with the raising of the presser foot and other operating mechanisms of the sewing machine. This higher mounting of the prior art cloth cutter attachments further requires that longer sewing needles be used, instead of standard length needles. Such longer needles tend to deflect or bend during stitching and thus the lines of stitching being sewn in the cloth can be off-centered or formed inaccurately.
Additionally, the size of such prior art designs generally has limited their use to or sewing gauges of one-quarter inch or less to avoid engagement of the presser foot by the knife mechanism, thus limiting the size of the pocket openings that can be formed in the cloth. A further problem with prior art cloth cutter attachments has been knife crashes. With previous designs, if the knife was not exactly aligned in the proper cutting position, the action of the sewing machine could cause the knife to drift slightly and become caught or bent and thus broken, or cause the fabric or cloth being sewn to be frayed or damaged. As a result, the cloth being sewn potentially would have to be discarded or fixed during later sewing operations, and the knife blades frequently have to be replaced.
Accordingly, it can be seen that a need exists for a cloth cutter attachment for a sewing machine for forming cut pocket openings in garments that is automatically actuatable so as to move from a cutting position in front of the sewing needles to a cutting position rearward of sewing needles without the knife becoming caught or bent, and which can be used with a standard sewing machine and standard length sewing needles without requiring modification of the sewing machine to accommodate the cloth cutter attachment.